Regulator compensator



7, 1936- F. H. GULLIKSEN Re. 19,807

aseumwon courmsuon (Original Filed Oct. 13, 1931 I I8 14 I I v 4! I '2 Q 7 if? 36' q |1| 'W .3; f

WITNESSES:

INIYVENTOR" BY 2/ g Y ATTORNEY Reissued Jan. 7, 1936 UNITED STATES PATENT OFFICE REGULATOR COMPENSATOB ram 11. Gulliksen,

Wilkinsburg, Pa... assignor to Westinghouse Electric & Manufacturing Company, a corporation of Pennsylvania 16, 1933, Serial Application for 7 Claims. (01. 111-312) My invention is directedto regulator compensators and has particular relation to load compensators for electronic-tube generatorvoltage regulators.

In the application of voltage regulators to electrical generators, it is frequently desired that the regulator change the value of voltage which it maintains as the load supplied by the generator changes. For example, where it is necessary to maintain constant the voltage at a. point distant from the generator that energizes the circuit, load-compensating means for the regulator are required because the voltage drop along the circuit conductors changes as the load on the circuit changes.

I have discovered that the desired compensation may be advantageously efiected in the case of electronic-tube regulators by taking advantage of the fact that as the load on a generator is increased, greater excitation is required to maintain the terminal voltage of the generator at a substantially constant value. I .have accordingly devised electronic-tube-regulator compensating means energized in accordance with the generator excitation rather than by the generator output and have found that, by the use of such an expedient, substantial savings in the cost of the compensating equipment may be efiected.

It is, accordingly, an object of my invention to provide a load compensator for an electronictube regulator applied to a dynamo-electric machine which operates in accordance with changes in the excitation of the machine.

A further object of my invention is to provide -a compensator of the type described which is particularly applicable to voltage regulators for electrical generators having separate exciters or other equivalent sources of field-winding-energizing current.

A still further object of my invention is to provide a load compensator for a.generator-voltage regulator utilizing an electronic tube controlgrid circuit, in which the additional equipment required is exceedingly small and inexpensive.

In practicing my invention, I provide means for introducing into the control-grid circuit of the generator-voltage-infiuenced electron tube a modifyingor compensating-control potential which varies in accordance with the excitation of the regulated generator.

My invention is particularly applicable to regulators for separately-excited generators, for in such applications I am permitted to attain the desired compensation merely by including in the gridcontrol circuit referred to, a resistor that In the form of the invention winding i8 is connected,

is energized either in accordance with the voltage of the generator field winding or in accordancewith the exciting current caused to flow through the winding. By this simple and inexpensive expedient I am able to change the value of the generated voltage in accordance with the changes in the load supplied by the generator.

My invention will best be understood from the following description of a specific embodiment thereof, when read together with the accompanying drawing, in which:

Figure 1 is a diagrammatic view of apparatus and circuits illustrating a preferred form of my invention applied to an electronic-tube voltage regulator for a direct-current generator having a separate exciter, and

Fig. 2 is a diagrammatic representation illustrating a second preferred form of my invention. disclosed in Fi 2 the compensating resistor vacuum-tube grid circuit is energized by the current flowing in the generator-field winding circuit, instead of from the voltage applied to energize the winding as in the modification shown in l.

Referring to Fig. 1 of the drawing, the generator to be regulated is indicated at Ill, it comprising armature windings connected with circuit conductors ii and I2 and a field winding II. A separate exciting generator I6, having a field in well known manner, to energize the generator field winding ll. Energizing current for the exciter-field winding l8 may be supplied from any suitable source such as from direct-current-energized circuit conductors and 2|.

The electronic-tube regulating system illustrated in the drawing is shown in simplified form in order that the functioning of my invention therein may be more clearly indicated. As illustrated, it comprises a single three-element vacuum tube 24 having anode and cathode elements 2i and 21, respectively, disposed in the energizing circuit oi. the exciter. field winding l8, and a grid or control element 28. Heating current for the cathode or filament 21 may belupplied in any suitable manner such as through a transformer energized from the alternating current circuit conductors 32 and 33.

The grid element as of the vacuum tube :4 is

connected in a control circuit which includes a standard potential battery 35 connected to act in opposition with the voltage of the regulated generator "I, a potentiometer or voltage-adjusting resistor 36 being included in this grid circuit;

disposed in the forms a part of the which is completed through a resistor 38 that load' compensator 01' my invention.

In the modification of the compensator illustrated in Fig. 1, resistor 38 is energized from the voltage impressed upon field winding l4, connection with the exciteror winding energizing conductors 40 and 4|, which are of positive and negative polarities, respectively, being made in the manner shown.

In the operation 01' the regulating system shown in Fig. l, the voltage of the generator Ill will be so controlled that the potential drop in that portion of resistor 35 included in the grid-control circuit is slightly greater than that of the standard potential battery 35, thus causing the potential of the grid element 28 of the vacuum tube 24 to be maintained at a negative value with respect to the cathode 21. For a particular value 01' the tube grid bias, the tube passes the proper amount 01' current to energize winding l8 sufliciently to maintain the voltage of generator I II at the normal or desired value mentioned.

A decrease in the voltage between conductors II and I2, from which resistor 36 is energized,

reduces the value of negative grid bias impressed upon the vacuum tube 24, thereby increasing the conducting properties 01' the tube and causing the excitation and voltage of exciter I 6 to be increased. This results in a corresponding increase in the excitation of generator l0 and the desired correction or the generator voltage.

' Similarly, an increase in the voltage of generator Ill acts to increase the value oi negative bias impressed upon vacuum tube 24 and to thus ei'lect a decrease in the voltage of the exciter l8 and of the excitation oi the generator II which results in a lowering oi the generator voltage back to the desired value.

Without the use of the resistor 38 in the gridcontrol circuit, it will be seen that the regulating system just described will maintain the voltage of the regulated generator Ill at substantially the same value independently of the loading of the generator; The change in value of grid bias required to change the exciting current of the exciter I! from the no load value'oi' the regulated generator to the full load value is a very small fraction or the generator voltage. It will i be seen that the eflect of this grid bias change for the diil'erent generator load conditions is to give the generator a slightly drooping voltage with increase in ice The action of the compensating means of my' invention causes the regulator to eilect'an increase in voltage asthe load increases. The re- ;sistor 33 introducesinto the control-grid circuit a potential which varies in accordance with the excitation of the regulated generator and hence in accordance with the load carried by the generator. It will be seen that this relation exists since ,asthe load on the generator is increased. the voltage-drop in the generator windings is proportionately increased, which necessitates that the induced voltage, and hence the excitation, be correspondingly increased with increasing load in order that the terminal voltage be maintained at the desired value. In practice, it

is found that this relation between generator load and excitation is sufliciently constant to permit of highly satisfactory load compensation.

Thus, in the system of Fig. 1, when the generator I0 is operating at low load values, the exciter voltage required to energize the field winding 14 is relatively low and the compensating As the load on the generator 0 is increased, 10

a greater excitation of the field quired to maintain the terminal action of the regulator causes the potential introduced into the grid winding is revoltage. The compensating circuit to be increased in accordance with the increase in the l.)

exciter voltage. By thus, in effect, adding to the voltage impressed upon the grid circuit by standard potential battery 35, this increased compensating potential lowers the value of negative grid bias impressed upon tube 24 and thus causes the 20 regulator to maintain the generator voltage at a correspondingly higher value, as an analysis of the grid control circuit will indicate. Conse quently, in the connection shown in Fig. 1, the compensating means of my invention act in the 2.3 manner to produce a rising-voltage-with-load characteristic of the regulator. The magnitude or degree of compensation, or the rate at which the compensating voltage is changed as the generator load changes may be controlled by in- :21 eluding greater or-lesser portions 01' resistor 38 4 in the grid-control circuit, such control being eiTected in the system of Fig. 1 by shifting a tap connection 43 along resistor 33.

It will be evident that a reversal in the con- 35 nections of the resistor 33 will cause the compensating action to function in the opposite manher to that just explained or to efl'ect a loweringvoltage-with-load characteristic of the regulating system, should such be desired. 40

It will be apparent that arrangements other than that shown in Fig. 1 may be utilized for introducing into the grid control circuit a compensating potential that varies in accordance with the excitation of the regulated generator. One such alternative scheme is shown in Fig. 2 in which the load compensating resistor 33' is connected in series-circuit relation with the energizing circuit 01' the generator field winding l4 instead of in parallel relation to this winding. 50

In .Fig. 2, the regulated generator l0 and the associated vacuum tube voltage regulating equipment is represented as being similar to that shown and described in Fig. 1, with the exception 01' the modification in the load compensating 55 means already mentioned. Consequently, a detailed description of the operation of thecomplete regulating system will not here be repeated.

It can beseen that the effect 01' the resistor 38' in the grid control circuit of vacuum tube 24 is 60 voltage compensation and a shift in the position 70 of tap connection 43' effects an adjustment of the magnitude of the compensation. i

It will be understood that the load-compensating meansof my invention may be applied to any electrical generatot having a separate excit 76 in: source controllable by electron tube means having a grid-control circultacted upon by a potential influenced by the voltage or the regulated generator, in which circuit the excitationresponsive compensating potential may be introduced by any suitable means. Hence my invention is applicable to a'wlde variety of electronictube regulators, including the more complicated types now known and utilized in the art.

While I have shown and described certain speciflc embodiments of my invention, I am fully trol potential determined by the machine voltage,

the combination oi means for introducing into said control circuit a machine-,excitation-determined potential which causes the regulator to characteristic. I i

2. In a voltage-regulating system for a dynamo-electric machine comprising an electronic tube adapted to control the machine excitation and a circuit ior impressing upon the tube a control potential which varies directly with the machine volgge, the combination of means for so introduc into said circuit a modiiying'potential which is determined by the machine excl tation as to cause the regulator to impart to the machine a rising voltage-with-load characteristic.

3. In a system comprising a dynamo-electric machine having a field winding, an exciter for energizing said winding, and a regulator comprising an electronic tube adapted to control the exby the machinevoltage, the combination 0! load gized by a measure of the exciter voltage and so connected in the tube-control circuit as to cause the combination of load-compensating means impart to the machine a rising voltage-with-load .7. In combination with a voltage-regulating citer voltage and a tube-control circuit influenced compensating means comprising a resistor eneracteristic.

the regulator to impart to the machine a rising voltage-with-load characteristic.

4. In a system comprising an electrical generator, means for supplying an exciting current thereto, and a voltage regulator comprising an 5 electronic tube adapted to control saidcur'rent and acircuit for impressing upon said tube a control potential which varies with the machine voltage, the combination of load compensating means comprising means for so introducing into said control circuit a modifying potential which varies with the machine exciting current as to cause the regulator to impart to the generator a rising-voltage-with-load characteristic.

5. In a voltage regulating system for an electrical generator comprising'an electronic tube adapted to control the generator excitation and a .circuit for impressing upon the tube a control potential which varies with the generator voltage,

comprising ,a resistor connected in the tube control circuit and means for so circulating through said resistor a generator-excitation determined current that the resulting resistor'voltage drop causes the regulator 'to impart to the generator a as rising voltage-with load characteristic.

6. Load-compensating means associated with anelectronic tube regulator adapted to control the voltage of an electrical generator comprising a resistor connected in the generator-voltage influenced tube control circuit of the regulator and means for so energizing said resistor by a measure of the generator exciting voltage as to cause the regulator to impart to the generator a rising voltage-with-load characteristic.

system for an electrical generator comprising an exclter for the generator, an electronic tube connected to adjust the voltage of the exciter, and means responsive to the voltage of the generator 40 for controlling the adjusting effect of the tube, generator-load compensating means for causing the exciter voltage to somcdify the tube adjust-' ing eflect that the regulating system imparts to the generator a rising voltage-with-load char- FIN H. GULIJKSEN. 

